Triple lift truck with continuous lift chain



Feb. 15, 1966 G. F. QUAYLE 3,235,034

TRIPLE LIFT TRUCK WITH CONTINUOUS LIFT CHAIN Filed Oct. 2, 1962 3Sheets-Sheet 1 INVENTOR Geo/ 5 H QUAYLE BY (W? G. F. QUAYLE 3,235,034

TRIPLE LIFT TRUCK WITH CONTINUOUS LIFT CHAIN Feb. 15, 1966 3Sheets-Sheet 2 Filed 001;. 2, 1962 INVENTOR 6 60 66 0041 45 A ow/ y Feb.15, 1966 G. F. QUAYLE 3,235,034

TRIPLE LIFT TRUCK WITH CONTINUOUS LIFT CHAIN Filed Oct. 2, 1962 3Sheets-Sheet 5 GEO/5s: F Qwms Arm YE) I S INVENTOR.

United States Patent C) 3,235,034 TRIPLE LIFT TRUCK WITH CONTINUOUS LlFTCHAIN George F. Quayle, Philadeiphia, Pa, assignor, by mesneassignments, to Yale & Towne, Inc., New York, N.Y.,

a company of Ohio Fiied Oct. 2, 1962, Ser. No. 227,773 Claims. (Cl.187-9) This invention relates to a lift truck utilizing a series oftelescoping extendible uprights, a lifting load carriage, and a multiplepiston lift ram for elevating the extendible uprights and the loadcarriage.

In trucks of this type, it is desirable that the load carriage havesubstantial free lift, i.e., vertical movement without verticalextension of the uprights. This allows the load carriage to be liftedwithout increasing the overall height of the truck, thereby permittingoperation of the loaded truck in areas of low overhead.

Various arrangements have been heretofore proposed for providing suchfree lift of a load carriage. One arrangement provides a shorttelescoping ram on the primary uprights, and through a series ofmultiplying sheaves and long lengths of lifting chains, effects the freelift of the load carriage and elevation of the uprights. The disadvantage of this arrangement is the necessity of providing long lengthsof chain and assembling the large number of multiplying sheaves.

Another arrangement for obtaining free lift provides a speciallyconstructed sequentially operating ram in which one part of the rammoves relatively to the other parts of the ram without increasing theoverall length of the ram. This movement of this part of the ram isutilized to effect the free lift, and subsequent extension of the ram isused to effect elevation of the uprights. The disadvantage of such anarrangement is that it requires a very expensive ram structure, and theram must operate in a particular sequence in which the one part movesrelatively to the other parts before the ram extends. In addition,relatively movable parts of the ram must be directly secured torelatively movable parts of the truck, so that there is a fixedrelationship between the ram operation and the movable uprights andcarriage.

My invention provides a lift truck in which substantial free lift isobtained without the use of a large number of multiplying sheaves andlong lengths of lifting chain, and in which free lift is assured Withoutregard to the sequence of operation of the parts of the ram. As afurther feature, the extension of the ram, while functioning to effectfree lift and full lift, is not mechanically particularly related to thelifting sequence of the carriage and uprights.

To this end, the truck of the invention includes a simple, multiplepiston telescoping ram having one part, normally the cylinder, mountedon the secondary uprights of the truck with the other parts, normallythe telescoping pistons, adapted to be extended upwardly relatively tothe part mounted on the secondary uprights. A sheave is mounted on thatpart of the ram which extends furthermost from the part mounted on thesecondary uprights, and a lift chain extends over the sheave on the ramand down around a sheave secured to the bottom of the secondaryuprights. The chain is attached at one end to the load carriage and atthe other end to the upper end of the primary uprights. The collapsedram is substantially shorter than the uprights and on initial extensionof the ram, the load carriage is lifted on the tertiary uprights whilethe uprights remain in the lowered position, whereby full free lift ofthe load carriage is obtained. Further extension of the ram results inlifting of the tertiary uprights relatively to the secondary uprightsand lifting of the secondary uprights relatively to the primaryuprights.

As a feature of the invention, the ram is mounted for slight rocking orpivotal movement on the secondary uprights, and the upper end of the ramis guided on the tertiary uprights, so that the ram is not subjected tobending or buckling due to deflection of the uprights under load.

Other objects and advantages of the invention will become apparent fromthe following description when read in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a perspective view of a lift truck constructed in accordancewith the invention, showing the uprights and load carriage in thelowered position;

FIG. 2 is a perspective view, similar to that of FIG. 1, but showing theuprights and load carriage in an elevated position;

FIG. 3 is a sectional view of the uprights and load carriage in theelevated position;

FIG. 4 is a sectional view taken on the line 4-4 of FIG. 3;

FIG. 5 is a sectional view taken on the line 55 of FIG. 3, showing themounting of the lift ram;

FIG. 6 is a schematic drawing of the uprights, load carriage, lift ramand lift chains, showing in full lines the fully lowered position of theload carriage, and showing in broken lines the position of the loadcarriage and lift ram after free lift of the load carriage; and

FIG. 7 is a schematic drawing, similar to that of FIG. 6, but showingthe tertiary uprights and secondary uprights partially elevated.

Referring to the drawings and in particular to FIGS. 1 and 2, the lifttruck 10 of the invention includes stationary or primary uprights 11,secondary uprights 12 mounted for vertical movement on the primaryuprights 11, tertiary uprights 13 mounted for vertical movement on thesecondary uprights 12, a load carriage 14 mounted for vertical movementon the tertiary uprights 13, and a lift ram 15 for elevating thesecondary uprights 12, the tertiary uprights 13 and the load carriage14.

In accordance with the invention, the left ram 15 is a simple multiplepiston ram including a cylinder 16, a first telescoping tubular piston17 mounted for sliding movement in the cylinder 16 and a secondtelescoping piston 13 mounted for sliding movement in the tubular piston17. The ram 15 may be of the construction shown in my copendingapplication, Serial No. 227,772, filed October 2, 1962 As shown in FIG.1, the ram 15, when unextended, has an overall length substantially lessthan that of the lowered uprights, thereby improving the visibility ofthe operator through the uprights. The cylinder 16 of the lift ram 15 ismounted on the secondary uprights 12 through a collar 19 which issecured to the cylinder 16 and which rests on brackets 20 which aresecured to the secondary uprights 12.

As best shown in FIGS. 3 and 5, the brackets 20 are secured to thesecondary uprights through a cross brace Ztla which is secured atopposite ends to the secondary uprights 12. Each bracket 20 has anupwardly projecting portion 21 providing a cylindrical outer surfacewhich fits into a cylindrical recess 22 formed in the lower side of thecollar '19, so that the cylinder 16 may rock slightly in a fore and aftdirection relatively to the secondary uprights 12. A strap 23 connectingthe projecting portions 21 on each side of the ram 15' preventsaccidental displacement of the collar 19 from the projecting portions21. As will be explained in detail hereafter, this mounting of thecylinder 16 of the ram 15 prevents the ram from being subjected tolateral bending stresses if the uprights deflect under load.

As best shown in FIGS. 1 and 4, the innermost piston 18 is' providedwith a cross head 24 which is secured to the outer end thereof andcarries sheaves 25. The sheaves 25 are mounted on integral hub portions26 extending from opposite sides of the cross head 24, and the sheaves25 are mounted for free rotation on the hubs 26 through suitableanti-friction bearings 27. A guide member 28 having a bifurcated endportion 29 is secured to each of the hub portions 26 of the cross head24 by suitable bolts 30. The bifurcations of the end portions 29 of eachguide member 28 extends on each side of a vertical guide rail 31 securedto the inner flange of each of the tertiary uprights 13 to guide theouter end of the inner piston 18 of the ram 15 during extension of theram 15. Thus, the ram cylinder 16 being mounted for pivotal or rockingmovement on the secondary uprights 12 through the collar 19 and thebrackets 20, and the outer end of the inner piston 18 being guidedthrough cooperation between guide members 28 on the outer end of thepiston 18 and the guide rails 31 on the tertiary uprights 13, the ram 15may rock or pivot so that the ram 15 is not subjected to lateral bendingor buckling due to deflection or bending of the uprights under load.

A pair of lift chains 32 are secured at one end to the load carriage 14through brackets 33, extend over the sheaves 25 carried by the crosshead 24 on the outer end of the inner piston 18, extend downwardlyaround a pair of sheaves 34 carried by the secondary uprights 12adjacent the lower ends thereof, and are anchored at their opposite endsto the upper ends of the primary uprights 11 at 35. As shown in FIG. 5,the sheaves 34 are conveniently mounted on the supporting brackets whichare secured to the secondary uprights 12 and support the cylinder 16 ofthe ram 15.

Referring now to FIG. 6, when fluid under pressure is introduced intothe cylinder 16 of the ram 15, the pistons 17 and 18 first extend,lifting the lead carriage 14 to the top of the tertiary uprights 13,through the chains 32, at twice the speed of the ram 15, while theuprights remain in the lowered position. Thus, full free lift of theload carriage is obtained.

When further upward movement of the load carriage 14 relatively to thetertiary uprights 13 is stopped through engagement of the load carriagewith stop members 36, which are secured to the upper ends of thetertiary uprights 13, further extension of the pistons of the ram liftsthe load carriage 14 and the tertiary uprights 13, through the chains 32at the same speed that the pistons of the ram 15 are extended relativelyto the secondary uprights 12. At the same time, the secondary uprights12, together with the lift ram 15, are lifted through the sheaves 34 andthe chains 32 relatively to the primary uprights 11, as shown in FIG. 7.This movement of the secondary and tertiary uprights 12 and 13 and theload carriage 14 continues until they reach the fully elevated positionas shown in FIG. 3.

During lowering of the load carriage, the reverse sequence takes placewith the tertiary uprights 13 and the secondary uprights 12 being firstlowered, and the load carriage thereafter being lowered relatively tothe tertiary uprights 13, until the load carriage is in the positionshown in solid lines in FIG. 6.

From the preceding description, it can be seen that there is provided alift truck in which free lift and full lift of the load carriage isobtained through the use of only two sets of sheaves, a pair of liftingchains having an overall length Which is not substantially greater thantwice the overall height of the uprights in the lowered position, and avery simple telescoping ram having a collapsed length substantiallyshorter than the overall height of the uprights in the lowered position.Further, no direct physical connection is necessary between therelatively movable parts of the lift ram and the uprights, while at thesame time, the load carriage and uprights are elevated in the propersequence, without regard to the sequence of movement of the parts of theram. Thus, the load carriage and the uprights are elevated in the propersequence whether both pistons of the ram are first extended together, orwhether the inner piston extends first and the outer piston extendsthereafter.

While one embodiment of the invention has been shown and described, itwill be appreciated that this is for the purpose of illustration andthat changes and modifications may be made therein without departingfrom the spirit and scope of the invention.

I now claim:

1. A lift truck comprising,

vertical primary uprights, vertically movable secondary and tertiarytelescoping uprights mounted on said primary uprights,

a load carriage mounted for vertical movement on said tertiary uprights,

a stop member for said load carriage on the tertiary uprights, saidcarriage directly engaging said stop member when said carriage reachesan upward limit of movement relative to the tertiary uprights,

an extensible lift ram having a series of relatively extensibletelescopic parts including a piston, and adapted to collapse to a lengthsubstantially less than the collapsed height of said uprights,

means mounting one of said parts of said ram on said secondary uprightsin a position in which the other parts of the ram extend upwardlyrelatively -to said one part when said ram is operated, said upwardlyextensible other parts of the ram being unsecured to said uprights so asto allow extending movement of said ram without moving any of saiduprights,

a sheave mounted on the part of said ram which extends furthermost fromsaid one part mounted on said secondary uprights,

a lift sheave secured to said secondary uprights adjacent the lower endthereof, and

a flexible lift element secured at one end to said load carriage,extending over said sheave on said ram, down around said lift sheave onsaid secondary uprights and attached at the other end to said primaryuprights adjacent the upper end thereof, whereby initial extension ofsaid ram effects free lift of said load carriage to the stop member onsaid tertiary uprights and further extension of said ram lifts saidtertiary uprights relatively to said secondary uprights and lifts saidsecondary uprights together with the lift ram relatively to said primaryuprights.

2. A lift truck comprising,

vertical primary uprights, vertically movable secondary and tertiarytelescoping uprights mounted on said primary uprights,

a load carriage mounted for vertical movement on said tertiary uprights,

a stop member for said load carriage on the tertiary uprights, saidcarriage directly engaging said stop member when said carriage reachesan upward limit of movement relative to the tertiary uprights,

a lift ram having a collapsed length substantially less than thecollapsed height of said uprights and having at least three telescopingparts extensible relatively to each other,

means pivotally mounting one of said parts of said ram on said secondaryuprights in a position in which the other parts of the ram extendupwardly relatively to said one part when said ram is operated, saidupwardly extensible other parts of the ram being unsecured to saiduprights so as to allow extending movement of said ram without movingany of said uprights,

a sheave mounted on the part of said ram which extends furthermost fromsaid one part mounted on said secondary uprights,

cooperating guide means on said tertiary uprights and on the upper endof said part of said ram which extends furthermost from said one part,whereby the upper end of said ram is guided and supported du i extensionof said ram while allowing the ram to rock on the pivotal mounting asthe uprights deflect,

a lift sheave secured to said secondary uprights adjacent the lower endthereof, and

a flexible lift element secured at one end to said load carriageextending over said sheave on said ram, down around said lift sheave onsaid secondary uprights and attached at the other end to said primaryuprights adjacent the upper end thereof, whereby initial extension ofsaid ram effects free lift of said load carriage to the stop member onsaid tertiary uprights and further extension of said ram lifts saidtertiary uprights relatively to said secondary uprights and lifts saidsecondary uprights together with the lift ram relatively to said primaryuprights.

3. A lift truck comprising,

vertical primary uprights, vertically movable secondary and tertiarytelescoping uprights mounted on said primary uprights,

a load carriage mounted for vertical movement on said tertiary uprights,

a stop member for said load carriage on the tertiary uprights, saidcarriage directly engaging said stop member when said carriage reachesan upward limit of movement relative to the tertiary uprights,

a lift ram having a collapsed length substantially less than thecollapsed height of said uprights and having a cylinder and at least twotelescopic pistons extendible from one and the same end of saidcylinder,

means mounting said cylinder of said ram on said secondary uprights in aposition in which said pistons extend upwardly relatively from saidcylinder when said ram is operated, said telescopic pistons beingunsecured to said uprights so as to allow extending movement of said ramwithout moving any of said uprights,

a she-ave mounted on the piston of said ram which extends furthermostfrom said cylinder mounted on said secondary uprights,

a lift sheave secured to said secondary uprights adja cent the lower endthereof, and

a flexible lift element secured at one end to said load carriage,extending over said sheave on said secondary uprights and attached atthe other end to said primary uprights adjacent the upper end thereof,whereby initial extension of said ram effects free lift of said loadcarriage to the stop member on said tertiary uprights and furtherextension of said ram lifts said tertiary uprights relatively to saidsecondary uprights and lifts said secondary uprights together with thelift ram relatively to said primary uprights.

4. A lift truck comprising,

vertical primary uprights, vertically movable secondary and tertiarytelescoping uprights mounted on said primary uprights,

a load carriage mounted for vertical movement on said tertiary uprights,

a lift ram having a collapsed length substantially less than the heightof said uprights and having a cylinder and at least two pistonstelescopically extendible in one direction from said cylinder,

means pivotally mounting said cylinder of said ram on said secondaryuprights in a position in which said pistons extend upwardly relativelyto said cylinder when said ram is operated,

a sheave mounted on the piston of said ram which extends furthermostfrom said cylinder mounted on said secondary uprights,

cooperating guide means on said tertiary uprights and on the upper endof said piston which extends the furthermost from said cylinder, wherebythe upper end of said ram is guided and supported during extension ofsaid ram while allowing said ram to rock on said secondary uprights asthe uprights deflect,

a lift sheave secured to said secondary uprights adjacent the lower endthereof, and

a flexible lift element secured at one end to said load carriage,extending over said sheave on said ram, down around said lift sheave onsaid secondary uprights and attached at the other end to said primaryuprights adjacent the upper end thereof, whereby initial extension ofsaid ram effects free lift of said load carriage on said tertiaryuprights and further extension of said ram lifts said tertiary uprightsrelatively to said secondary uprights and lifts said secondary uprightstogether with the lift ram relatively to said primary uprights.

5. A lift truck comprising fixed vertical primary uprights, verticallymovable secondary and tertiary telescoping uprights mounted on saidprimary uprights, a load carriage mounted for vertical movement on saidtertiary uprights, a stop member for said load carriage on the tertiaryuprights, said carriage directly engaging said stop member when saidcarriage reaches an upward limit of movement relative to the tertiaryuprights, a hydraulic lift ram having a series of relativelymoveabletelescopic parts extendible relatively to one another uponapplication of fluid pressure to said ram, means mounting one of saidparts of said ram on said secondary uprights in a vertical position forextension the other parts of said ram upwardly vertical rela-tively tosaid secondary uprights when said ram is actuated, said upwardlyextensible other parts of the rams being unsecured to said uprights toallow extending movement of said ram without moving any of saiduprights, a sheave mounted adjacent the upper end of the uppermostextendible part of said ram when collapsed, said ram being of suchoverall length that when mounted on said secondary uprights the upperend of said ram and said sheave are considerably below the upper ends ofsaid uprights so that free lift extension of said ram is possible, asecond lift sheave secured relatively to said secondary uprightsadjacent to the lower end thereof, and a flexible lift element securedat one end to said carriage, extending over said ram sheave anddownwardly under said second lift sheave and then upwardly to saidprimary uprights and fixed to said primary uprights.

References Cited by the Examiner UNITED STATES PATENTS 722,444 3/1903Bouck 187-9 2,595,120 4/1952 Barnes 187-9 2,666,501 1/1954 Abbe 187-92,670,811 3/ 1954 'Shafler 187-9 2,918,143 12/1959 Shaffer 187-92,936,047 5/ 1960 Quayle 187-9 XR 2,979,162 4/1961 Quayle 187-92,987,140 6/1961 Olson 187-9 3,077,951 2/1963 Ramsey 187-9 3,116,8121/1964 Farmer 187-9 LOUIS J. DEMBO, Primary Examiner.

ANDRES H. NIELSEN, SAMUEL F. COLEMAN,

Examiners.

1. A LIFT TRUCK COMPRISING, VERTICAL PRIMARY UPRIGHTS, VERTICALLYMOVABLE SECONDARY AND TERTIARY TELESCOPING UPRIGHTS MOUNTED ON SAIDPRIMARY UPRIGHTS, A LOAD CARRIAGE MOUNTED FOR VERTICAL MOVEMENT ON SAIDTERTIARY UPRIGHTS, A STOP MEMBER FOR SAID LOAD CARRIAGE ON THE TERTIARYUPRIGHTS, SAID CARRIAGE DIRECTLY ENGAGING SAID STOP MEMBER WHEN SAIDCARRIAGE REACHES AN UPWARD LIMIT OF MOVEMENT RELATIVE TO THE TERTIARYUPRIGHTS, AN EXTENSIBLE LIFT RAM HAVING A SERIES OF RELATIVELYEXTENSIBLE TELESCOPIC PARTS INCLUDING A PISTON, AND ADAPTED TO COLLAPSETO A LENGTH SUBSTANTIALLY LESS THAN THE COLLAPSED HEIGHT OF SAIDUPRIGHTS, MEANS MOUNTING ONE OF SAID PARTS OF SAID RAM ON SAID SECONDARYUPRIGHTS IN A POSITION IN WHICH THE OTHER PARTS OF THE RAM EXTENDUPWARDLY RELATIVELY TO SAID ONE PART WHEN SAID RAM IS OPERATED, SAIDUPWARDLY EXTENSIBLE OTHER PARTS OF THE RAM BEING UNSECURED TO SAIDUPRIGHTS SO AS TO ALLOW EXTENDING MOVEMENT OF SAID RAM WITHOUT MOVINGANY OF SAID UPRIGHTS,